Morphometric Techniques Research Articles

Forelimb morphology as an adaptation for burrowing in kangaroo rat species (genus Dipodomys) that inhabit different soil substrates

Abstract Among burrowing rodents, forelimb morphology frequently shares an intricate relationship with soil substrates. Soils vary widely in texture and density, leading to differences in friability (e.g., the relative ability of particles to be broken apart), which often requires forelimb specializations in digging animals. Kangaroo rats (Dipodomys spp.) dig and occupy burrows, a trait that is essential to their survival. Some Dipodomys species are restricted to particular substrates that presumably require species-specific forelimb traits. Here we examined the forelimb morphology and soil substrates inhabited by range-restricted and widely ranging Dipodomys species to explore the variation in soil usage, forelimb specializations, and the relationship between these traits. We assessed size and shape traits of preserved specimen forelimb bones using traditional and geometric morphometric techniques and extracted soil data associated with the collecting locality of each specimen. We expected species that inhabit dense soil substrates to display specialized forelimb morphology typified by an elongated scapula and robust humerus, radius, and ulna. The species differed substantially in their soil associations and forelimb morphologies. In particular, forelimb traits that enhance mechanical digging ability were detected in D. elator, a range-restricted species that inhabits dense clay-rich soils. These findings suggest that Dipodomys species that inhabit dense substrates may require correspondingly specialized forelimb morphology and that these traits may limit the desirable geographic ranges inhabited by these species. This may provide important information when making conservation decisions given that unlike other habitat features, soil substrates cannot be easily modified to suit the needs of the organism.

Sexual dimorphism in the cranium and endocast of the eastern lowland gorillas (Gorilla beringei graueri)

Sexual dimorphism of the nervous system has been reported for a wide range of vertebrates. However, understanding of sexual dimorphism in primate cranial structures and soft tissues, and more particularly the brain, remains limited. In this study, we aimed to investigate the external and internal (i.e., endocast) cranial differences between male and female eastern lowland gorillas (Gorilla beringei graueri). We examined the differences in the size, shape, and disparity with the aim to compare how sexual dimorphism can impact these two structures distinctively, with a particular focus on the endocranium. To do so, we reconstructed gorilla external crania and endocasts from CT scans and used 3D geometric morphometric techniques combined with multivariate analyses to assess the cranial and endocranial differences between the sexes. Our results highlighted sexual dimorphism for the external cranium and endocast with regard to both size and shape. In particular, males display an elongated face accompanied by a pronounced sagittal crest and an elongated endocast along the rostroposterior axis, in contrast to females who are identified by a more rounded brain case and endocast. Males also show a significantly larger external cranium and endocast size than females. In addition, we described important differences for the posterior cranial fossae (i.e., the position of the cerebellum within the brain case) and olfactory bulb between the two sexes. Particularly, our results highlighted that, relatively to males, females have larger posterior cranial fossae, whereas males have been characterized by a larger and rostrally oriented olfactory bulb.

Morphometric Differentiation of the Swimming Crab Portunus sanguinolentus (Herbst, 1783) Populations in East Asia: Implications for Stock Identification and Management

Morphometric disparities were employed to characterize the geographical variations in and elucidate the phylogeography of Portunus sanguinolentus in East Asia. In this study, a comprehensive assessment was undertaken based on measurements from 833 individual crabs. These crabs were sampled from eight distinct locations, namely Kyushu (KS), Fuzhou (FZ), Yilan (YL), Xiamen (XM), Tainan (TN), Hong Kong (HK), Vietnam (VN), and Singapore (SG). Twelve morphometric measurements were standardized based on size using the allometric method. A cluster analysis and a canonical variate analysis (CVA) were then conducted for a data analysis. Randomization tests were subsequently performed to validate the morphometric differences observed among the groups. The analytical results classified the eight sampled populations into at least two distinct clusters. The first cluster included three samples from China (specifically FZ, XM, and HK), while the second cluster consisted of samples from East Asia (including KS, YL, TN, VN, and SG). The CVA revealed a tripartite division into three groups: the mainland China group (FZ, XM, and HK), the Kuroshio group (KS, YL, and TN), and the Southeast Asia group (VN and SG). The observed morphometric variations between these broad groups were statistically significant for both genders. These differences may be attributed to evolutionary origins, geographical events, or environmental adaptations. This study highlights the effectiveness of morphometric techniques in providing comprehensive insights into species delimitation and philogeographic relationships.

Neuroprotective effect of Potentilla reptans L. root in the rat brain global ischemia/reperfusion model.

Stroke is the most common cause of death among neurological diseases. The protective effects of Potentilla reptans L. include antioxidative, anti-inflammatory, and antiapoptotic effects. In this study, the brain protection and beta-amyloid effects of P. reptans root extract were investigated in the rat brain ischemia/reperfusion (IR) model. Forty male Wistar rats were randomly divided into five groups (n = 8), including IR, sham, and three groups receiving P. reptans with concentrations of 0.025, 0.05, and 0.1 (g/kg/b.w.), which were injected daily for 7 days. For the IR model, the common carotid artery was occluded bilaterally for 8 min. All injections were intraperitoneal (IP). The shuttle box test was used to measure passive avoidance memory. Then the brain tissue was extracted for the histological examination of neuron counts and β-amyloid plaques using a morphometric technique, and finally, Statistical Package for the Social Sciences software was used for statistical analysis of the data. Pretreatment with P. reptans improved memory impairment. Also, by examining the tissues of the CA1, CA3, and dentate gyrus areas of the hippocampus, it was observed that the number of plaques in the groups receiving P. reptans extract was reduced compared to the IR group, especially at the concentration of 0.05 g/kg/b.w. Also, P. reptans improved the number of neurons at all concentrations, in which the concentration of 0.05 g/kg/b.w. showed more effective therapeutic results. Taken together, we found that P. reptans root extract has beneficial effects on memory impairment, neuronal loss, and β-amyloid accumulation.

Morphological Variability of a Rare Species Zygophyllum pinnatum in the South Urals and Adjacent Territories

When working with rare plant species, applying morphometric techniques is one of the main ways to obtain a representative data set on plant individuals and the state of particular populations growing in different ecological conditions and experiencing different degrees of anthropogenic load. Zygophyllum pinnatum, an understudied species growing on the territory of the Republic of Bashkortostan, the Orenburg region, and the Republic of Kazakhstan, is referred as a rare species. The purpose of the work is to study morphometric parameters and reveal the vitality structure of the Z. pinnatum coenopopulations in two regions of the Russian Federation (the Republic of Bashkortostan and Orenburg region) and in the north-west of the Republic of Kazakhstan (the Aktobe Region). Applying standard morphometric techniques, we analyzed the state of 16 coenopopulations of the species. Judging by most morphometric parameters, the leadership belongs to the individuals from the “Troitsk Cretaceous Mountains” coenopopulation located in the Sol-Iletsky District of Orenburg oblast, where, apparently, the most optimal plant conditions are formed (the absence of human impact and low projective cover of the grass stand to have a favorable effect). The minimum values for most parameters are recorded in the coenopopulations located on the territory of the Republic of Kazakhstan, resulting from arid growing conditions. The variability of most characters is within the normal range of the species response (Cv—5.0–44.6%). The discriminant function analysis revealed the morphostructural similarity of individuals from most coenopopulations. Regarding vitality, eight coenopopulations are prosperous, and another eight are depressed. The condition of the species coenopopulations is stable; however, the species is not provided with proper protection measures. Therefore, further monitoring of its habitats and improvement of environmental measures are necessary.

Patterns in Wing Morphology and Fluctuating Asymmetry in Eulaema nigrita along an Altitudinal Gradient in the Brazilian Rupestrian Grassland.

Mountain ecosystems experience abrupt abiotic changes that represent environmental filters for many organisms, shaping their phenotypic expressions. However, little is known about the morphological and symmetric adjustments of native bees along altitudinal gradients. We evaluated the changes on wing morphology, wing size, and vein fluctuating asymmetry (FA) of Eulaema nigrita Lepeletier (Apidae: Euglossini) associated with climatic variables along an altitudinal gradient in the rupestrian grassland (known also as campo rupestre or rupestrian field) of Serra do Cipó, Brazil. Seven sampling points along the altitudinal gradient were selected and distributed among 800 and 1400m.a.s.l., and then, 40 individuals of E. nigrita were collected per each altitudinal point to determine the FA levels and the morphological changes using geometric morphometric techniques. We found that the wing size of E. nigrita decreased with increasing altitude. At the highest altitudes, the levels of FA of the wing veins were greater compared to bees from lower altitudes. We detected significant changes in wing morphology along the altitudinal gradient; bees of lower altitudes showed longer and wider wings than bees of higher altitudes, which had narrower and less elongated wings. Our results show a set of morphological adjustments and phenotypic expressions in E. nigrita associated with the variation in environmental conditions along the altitudinal gradient. We highlight the importance of environmental variables as insect-stressor factors, and that FA and geometric morphometric can be excellent tools for monitoring and evaluating environmental stresses.

Are we there yet? Inter- and intraspecific approaches to evaluating phenotypic optima in a range expanding East African fish, Enteromius apleurogramma (Cyprinidae)

Abstract We explored how range expansion of freshwater fishes coincident with climate warming is affected by, and then in turn affects, responses to a second environmental gradient; dissolved oxygen. Traits related to hypoxia tolerance, specifically various metrics of gill size and geometric morphometric proxies of gill size were quantified for a range-expanding cyprinid fish (Enteromius apleurogramma) in both its historical and novel ranges in the Mpanga River drainage of Uganda, East Africa. We found that E. apleurogramma followed patterns previously established in the congener E. neumayeri. Gill filament length and some other metrics were strongly divergent in long-established populations of both E. apleurogramma and E. neumayeri, with larger gills in hypoxic populations compared to normoxic ones. Range-expanding populations were intermediate to the two long-established populations, but divergent between themselves. Other gill traits such as filament number were weakly or not divergent. Furthermore, we show that grosser morphological traits such as opercular area can be successfully used as a proxy for gill size, both by direct measurement as well as using geometric morphometric techniques. Finally, we show that both parapatric conspecific populations and sympatric heterospecific populations can be used as reference points to approximate the ‘target’ of adaptation to hypoxic conditions.

Comparing shell size and shape with canonical variate analysis of sympatric Biomphalaria species within Lake Albert and Lake Victoria, Uganda

Abstract The Great African Lakes in Uganda (Lake Albert and Lake Victoria) are known habitats to several sympatric species of Biomphalaria, intermediate snail hosts of the human parasite Schistosoma mansoni. However, accurate identification of snails by morphology alone can be problematic, highlighting a need for robust, on-site identification methods, since only certain species have important roles in parasite transmission. This study investigates the conchological variation within Biomphalaria species collected from these two Great East African Lakes. We compared the shell morphologies of Biomphalaria species using landmark-based morphometric techniques and were able to distinguish Biomphalaria species through canonical variate analysis (CVA) of the apical and apertural shell angles. After identification with molecular methods, three Biomphalaria species (B. pfeifferi, B. stanleyi, and B. sudanica), with heterogenous occurrences along the shoreline, were identified at Lake Albert that could be differentiated from one another using CVA of apical and apertural datasets; by contrast, a single Biomphalaria species was identified at Lake Victoria (B. choanomphala). When snails from both lakes were compared together, CVA was able to differentiate all four species using the apical dataset but not the apertural dataset. Of the Biomphalaria species identified, ecological phenotypic variation was only found in B. choanomphala, which exhibited two distinct ecological morphotypes. Furthermore, these two B. choanomphala morphotypes from Lake Victoria overlapped upon analysis of the apical dataset, yet were clearly separated upon analysis of the apertural dataset. Our study demonstrates that landmark-based morphometrics could play a future role in distinguishing sympatric Biomphalaria species in Uganda.

Comparative evaluation of glomerular morphometric techniques reveals differential technical artifacts between focal segmental glomerulosclerosis and normal glomeruli.

Morphometric estimates of mean or individual glomerular volume (MGV, IGV) have biological implications, over and above qualitative histologic data. However, morphometry is time-consuming and requires expertise limiting its utility in clinical cases. We evaluated MGV and IGV using plastic- and paraffin-embedded tissue from 10 control and 10 focal segmental glomerulosclerosis (FSGS) mice (aging and 5/6th nephrectomy models) using the gold standard Cavalieri (Cav) method versus the 2-profile and Weibel-Gomez (WG) methods and a novel 3-profile method. We compared accuracy, bias and precision, and quantified results obtained when sampling differing numbers of glomeruli. In both FSGS and controls, we identified an acceptable precision for MGV of 10-glomerular sampling versus 20-glomerular sampling using the Cav method, while 5-glomerular sampling was less precise. In plastic tissue, 2- or 3-profile MGVs showed greater concordance with MGV when using Cav, versus MGV with WG. IGV comparisons using the same glomeruli reported a consistent underestimation bias with both 2- or 3-profile methods versus the Cav method. FSGS glomeruli showed wider variations in bias estimation than controls. Our 3-profile method offered incremental benefit to the 2-profile method in both IGV and MGV estimation (improved correlation coefficient, Lin's concordance and reduced bias). In our control animals, we quantified a shrinkage artifact of 52% from tissue processed for paraffin-embedded versus plastic-embedded tissue. FSGS glomeruli showed overall reduced shrinkage albeit with variable artifact signifying periglomerular/glomerular fibrosis. A novel 3-profile method offers slightly improved concordance with reduced bias versus 2-profile. Our findings have implications for future studies using glomerular morphometry.

Evolution of the Limpopo River Basin in Botswana based on morphometric and morphotectonic features from selected rivers using GIS techniques

ABSTRACT This study used morphometric techniques to generate new information describing the evolution and hydrogeological behaviour of the Limpopo River Basin in Botswana, based on the analysis of drainage surface features, form, and size. Drainage basins provide basic information on their evolution, which, when quantified, yield information on the interaction between tectonics, climatic, and surface processes. Drainage networks were extracted from the Shuttle Radar Topographic Mission (SRTM) Digital Elevation Model (DEM) (90 m × 90 m), and subsequently, morphometry indices were computed using ArcGIS 10.5. Drainage network extraction was performed using the Arc Hydro extension in ArcGIS 10.5. ArcGIS 10.5 image processing technique was used to extract lineaments and create rose diagrams. The results showed that the Limpopo sub-basins in Botswana were drained by fourth- and fifth-order streams, with a total drainage area of 107, 871 km2. Additionally, the basin asymmetry and mean bifurcation ratios showed tilting in the sub-basins, suggesting tectonic instability and structural control in a low – to-moderate active tectonic zone. The sub-basins also had a coarse texture, indicating a high infiltration capacity. These results are essential for planning and managing watershed systems, flood risk assessment, and potential groundwater assessment for the different sub-basins of the Limpopo River Basin in Botswana.

Toxic effect of Callistemon viminalis essential oil on the ovary of engorged Rhipicephalus microplus female ticks (Acari: Ixodidae).

Rhipicephalus microplus is the main ectoparasite of cattle and its parasitism can reduce weight gain of hosts, in addition to causing anemia, increasing the risk of myiasis, and resulting in the transmission of Babesia bovis and Anaplasma marginale, among other pathogens. The use of synthetic chemicals plays an important role in controlling these ticks. However, its frequent and indiscriminate use has contributed to the selection of resistant strains, resulting in greater interest in the search for natural-origin products. The shrub Callistemon viminalis (Myrtaceae), also known as weeping bottlebrush, is known for its antibacterial, acaricidal, repellent, and antifungal activities, but there are no reports in the literature about its effects on the internal morphology of ticks. This study aimed to extract and characterize the essential oil obtained from the leaves of C. viminalis. Additionally, its effects on the ovary morphology of engorged R. microplus were assessed through histological, histochemical, and morphometric techniques. Exposure to C. viminalis caused dose-dependent morphological changes, such as cellular alterations in the epithelial layer lining the ovary lumen and the pedicel, irregularity of the chorion and oocyte shape, changes in protein and carbohydrate content, decrease in oocyte size, reduction in the size of the nucleus as well as cytoplasmic and nucleolar vacuolation. Thus, C. viminalis essential oil exhibited a toxic effect on the reproductive system of R. microplus, which may result in the reproductive impairment of this tick species.

Complex plumages spur rapid color diversification in kingfishers (Aves: Alcedinidae).

Colorful signals in nature provide some of the most stunning examples of rapid phenotypic evolution. Yet, studying color pattern evolution has been historically difficult owing to differences in perceptual ability of humans and analytical challenges with studying how complex color patterns evolve. Island systems provide a natural laboratory for testing hypotheses about the direction and magnitude of phenotypic change. A recent study found that plumage colors of island species are darker and less complex than continental species. Whether such shifts in plumage complexity are associated with increased rates of color evolution remains unknown. Here, we use geometric morphometric techniques to test the hypothesis that plumage complexity and insularity interact to influence color diversity in a species-rich clade of colorful birds-kingfishers (Aves: Alcedinidae). In particular, we test three predictions: (1) plumage complexity enhances interspecific rates of color evolution, (2) plumage complexity is lower on islands, and (3) rates of plumage color evolution are higher on islands. Our results show that more complex plumages result in more diverse colors among species and that island species have higher rates of color evolution. Importantly, we found that island species did not have more complex plumages than their continental relatives. Thus, complexity may be a key innovation that facilitates evolutionary response of individual color patches to distinct selection pressures on islands, rather than being a direct target of selection itself. This study demonstrates how a truly multivariate treatment of color data can reveal evolutionary patterns that might otherwise go unnoticed.

Sex dimorphism in the deutonymphs of Dermanyssus gallinae (De Geer, 1778) based on geometric morphometrics

The lifecycle of poultry red mite (PRM), Dermanyssus gallinae,includes several stages and only the adult has been reported to have sex discrimination based on body structures and color patterns. Currently, it's still unknown how to distinguish two sexes of deutonymphs. We measured body length of 254 engorged deutonymphs and examined body size and shape variation of 104 engorged deutonymphs using geometric morphometric techniques. Our findings showed that deutonymph females (with average values of 813.08 μm) had a longer body length than deutonymph males (713.39 μm). Additionally, deutonymph females were found to had a narrow and elongated posterior body shape while deutonymph males had a suboval shape, and the former was bigger than the latter. These results suggest that there is sexual dimorphism in PRM deutonymphs, and the differentiation of deutonymph females and males based on their body length, shape, and size will facilitate a better understanding of reproductive behavior and the accurate population dynamics of PRMs.

Basicranial Modular Organization. A Study in the Araucanian Horse of Colombia.

The skull is divided into neurocranium and splanchnocranium, and its variation allows ecomorphological studies to learn about possible evolutionary and adaptive characteristics. The basicranial organization of the neurocranium and splanchnocranium modules was studied in a sample of 31 skulls from adult Araucanian horses by means of 2D geometric morphometric techniques. The neurocranium and splanchnocranium modules on the ventral aspect were analyzed separately using a set of 31 landmarks. The RV coefficient (the multivariate analog of a correlation) was estimated to analyze the independence of these two parts, as well as their morphological integration, using a two-block analysis of least squares. The study results confirm the modular development of the neurocranium and the splanchnocranium, the former being more stable than the latter as well as low morphological integration between the two. The development between both parties is structured in a modular way but allows relative independence. Now it would be interesting for future studies to add muscles (those that connect the cranial parts, but also the cervical), the hyoid apparatus, and the ossicles of the internal ear and the jaw and analyze if they behave as integrated modules between them. Since this research has been conducted at the subspecific breed level, it could be plausible that in other breeds, this integrative development was different.

Seasonal changes in plumage density, plumage mass, and feather morphology in the world’s northernmost land bird, the Svalbard Rock Ptarmigan (Lagopus muta hyperborea)

The Svalbard Rock Ptarmigan, Lagopus muta hyperborea, is the only year-round resident terrestrial bird in the high Arctic. Many of the physiological and morphological adaptations permitting its winter endurance in this harsh environment are well understood. However, it remains unknown how the conspicuous moult from a greyish brown summer to a white winter plumage, and any underlying changes in plumage structure and feather morphology, contribute to seasonal acclimatisation. We used standard morphometric techniques to describe the seasonal change in plumage and feather characteristics in six body regions. Then, we investigated whether winter plumage traits differed between first-winter and adult (second winter, or older) birds, because a difference in coat insulation has been suggested as an explanation for why first-winter Svalbard Ptarmigan loose more heat than adults. Plumage feather density (i.e., feathers × cm−2) and mass density (i.e., mg feathers × cm−2) were higher in winter, particularly on the head and feet where individual feathers were also heavier, longer, and downier. Seasonal changes in other regions (back, tarsi) indicated acclimatisation primarily to resist physical wear and wind. First-winter and adult birds had similar feather densities. However, mass density in first-winter birds was significantly lower than in adults in all but one body region (back) because individual feathers weighed less. This can explain previous observations of higher heat loss rates in first-winter birds. Our study suggests that plumage acclimatisation contributes to optimising the winter phenotype of Svalbard Rock Ptarmigan, both through higher insulative capacity and by improved resistance to harsh weather. The extent of these adaptations may be determined by the time or energy available for feather growth, exemplified here by inferior insulation in first-winter birds.

2D Geometric morphometrics of the first lower molar of the genus Meles Brisson, 1762 including new badger evidence from the Lower Pleistocene Quibas site (Murcia, Spain)

Badgers belong to the genus Meles Brisson, 1762, which comprise four extant species (M. anakuma Temminck, 1844, M. leucurus (Hodgson, 1847), M. canescens Blanford, 1875, and M. meles (Linnaeus, 1758)). The genus is included in the subfamily Melinae Bonaparte, 1838, a polyphyletic group of Eurasian mustelids whose evolutionary relationships need further clarification. The evolutive relationships of the genus are complex and far from being resolved. This work aims to describe a nearly 1 Ma unpublished badger mandible from the Sierra de Quibas (Murcia) and to help clarify the evolutionary patterns of Euroasiatic badgers. To this end, we used 2D geometric morphometric techniques to measure 57 landmarks and semilandmarks in 79 first lower molars (m1) of Meles, ranging from Pleistocene to extant species. Our results show evidence for differentiating between primitive badgers and living species of Meles. The new m1 of Meles from the Quibas site is more gracile (relatively narrower and longer) than the other Eurasian extinct species, and shows that this specimen can be placed in the subspecies M. meles meles (Linnaeus, 1758). Our results also show that the denomination of M. meles atavus Kormos, 1914 as a related subspecies with a primitive morphology is morphologically supported. Therefore, we conclude that the living subspecies of badger M. meles meles was already differentiated in the south of the Iberian Peninsula at around 1 Ma, but some primitive remnant populations persisted in the north of the Iberian Peninsula, for which we recognize the subspecies M. meles atavus.

Unique fiber phenotype composition and metabolic properties of the stapedius and tensor tympani muscles in the human middle ear.

The middle ear muscles have vital roles, yet their precise function in hearing and protection remains unclear. To better understand the function of these muscles in humans, the morphology, fiber composition, and metabolic properties of nine tensor tympani and eight stapedius muscles were analyzed with immunohistochemical, enzyme-histochemical, biochemical, and morphometric techniques. Human orofacial, jaw, extraocular, and limb muscles were used as references. The immunohistochemical analysis showed that the stapedius and tensor tympani muscles were markedly dominated by fibers expressing fast contracting myosin heavy chain MyHC-2A and MyHC-2X (79 ± 6% vs. 86 ± 9%, respectively, p=0.04). In fact, the middle ear muscles had one of the highest proportions of MyHC-2 fibers ever reported for human muscles. Interestingly, the biochemical analysis revealed a MyHC isoform of unknown identity in both the stapedius and tensor tympani muscles. Muscle fibers containing two or more MyHC isoforms were relatively frequently observed in both muscles. A proportion of these hybrid fibers expressed a developmental MyHC isoform that is normally absent in adult human limb muscles. The middle ear muscles differed from orofacial, jaw, and limb muscles by having significantly smaller fibers (220 vs. 360 μm2 , respectively) and significantly higher variability in fiber size, capillarization per fiber area, mitochondrial oxidative activity, and density of nerve fascicles. Muscle spindles were observed in the tensor tympani muscle but not in the stapedius muscle. We conclude that the middle ear muscles have a highly specialized muscle morphology, fiber composition, and metabolic properties that generally showed more similarities to orofacial than jaw and limb muscles. Although the muscle fiber characteristics in the tensor tympani and stapedius muscles suggest a capacity for fast, fine-tuned, and sustainable contractions, their difference in proprioceptive control reflects different functions in hearing and protection of the inner ear.

Role of nalas in development of landforms and land use pattern with special reference to the Stakmo village, Leh valley

In the Leh valley, apart from the river Indus, several nalas have a great significance on development of a number of villages and settlement areas. The present work is an effort to illustrate the pivotal role of the Stakmo nala in establishment of the Stakmo village. The study also seeks to emphasis the necessity of the nala basin management to sustain the natural resources for the existence of the villages. Various problems related with Leh city and its adjacent area have been studied by several scientists. However, most of the scientists hardly show interest in depicting the comprehensive roles of the different nalas for the construction of many settlement areas and their related issues in the Leh valley. Present authors have tried to unfold the role of nalas in development of landforms and land use pattern with special reference to Stakmo village, Leh valley. Along the Leh valley there are11 important nalas which have key role to supply necessary natural resources to develop a number of important villages and settlement areas. Undoubtedly, availability of natural resources of an area greatly influenced by the process of landform development and their characteristics, because landscape characteristics play a significant role in generation of local natural resources. Hence, in order to illustrate the significant role of the Stakmo nala in development of landforms and land use pattern in Stakmo village and its adjacent area, the authors analysed vivid geomorphic features of the Stakmo nala basin based on quantitative approach including morphometric techniques and field observation. Apart from morphometric analysis, field based data regarding nala sediment size, rock types, micro features, varied land use pattern of the Stakmo village including perception study of the local people have been tried to discuss in the work.

Community-scale relationships between body shape and trophic ecology in tropical demersal marine fish of northeast Brazil.

Functional morphology investigates the relationships between morphological characters and external factors, such as environmental, physical and ecological features. Here, we evaluate the functional relationships between body shape and trophic ecology of a tropical demersal marine fish community using geometric morphometrics techniques and modelling, hypothesizing that shape variables could partially explain fish trophic level. Fish were collected over the continental shelf of northeast Brazil (4-9°S). Analysed fish were distributed into 14 orders, 34 families and 72 species. Each individual was photographed in lateral view, and 18 landmarks were distributed along the body. A principal component analysis (PCA) applied on morphometric indices revealed that fish body elongation and fin base shape were the main axes of variation explaining the morphology. Low trophic levels (herbivore and omnivore) are characterized by deep bodies and longer dorsal and anal fin bases, while predators present elongated bodies and narrow fin bases. Fin position (dorsal and anal fins) on the fish body is another important factor contributing to (i) body stability at high velocity (top predators) or (ii) manoeuvrability (low trophic levels). Using multiple linear regression, we verified that 46% of trophic level variability could be explained by morphometric variables, with trophic level increasing with body elongation and size. Interestingly, intermediate trophic categories (e.g., low predators) presented morphological divergence for a given trophic level. Our results, which can likely be expanded to other tropical and nontropical systems, show that morphometric approaches can provide important insights into fish functional characteristics, especially in trophic ecology.

Morphometric technique to determine the age of adult Asian elephants (<em>Elephas maximus</em>) in relation to their frontal neurocranial phenotype

The Ceylon Journal of Science is a peer-reviewed journal published quarterly by the University of Peradeniya, Sri Lanka in March, June, September and December. It is aimed at publishing high quality research articles on topics related to different disciplines in Science. The journal accepts original research articles, book reviews, reviews and mini-reviews, short communications, opinions, research notes, and commentaries and notes. The Journal has its own website https://site.pdn.ac.lk/cjs/. The journal strictly adheres to publication ethics as emphasized by the Committee on Publication Ethics (COPE). It is indexed in Sri Lanka Journals Online (SLJOL), Directory of Open Access Journals (DOAJ), Google Scholar and Zoological Records. According to the Google Scholar;H5-Index: 12H5-Median: 15According to the Exaly (1970 – 2021);Impact Factor: 0.6 (top 19%)Extended IF: 0.6 (top 19%)H-Index: 8 (top 28%)Citations/paper: 1.42